Asymmetric bi-directional teleportation scheme in the presence of a Mentor and a controller

Abstract

In this paper a quantum communication protocol is proposed for the purpose of the exchange of a single qubit and a three-qubit state between two parties. It is a bi-directional teleportation protocol where the two parties have no information about the states they possess. The protocol has a Mentor who initiates the process and by measurement fixes the course of it amongst several possible alternatives. The participants are not initially connected through a single entangled state. It is the action of the Mentor which creates a seven-qubit entanglement amongst the legitimate parties. The role of the Mentor ends thereby. There is a Controller to oversee the process whose action leads to the completion of the protocol. The efficiency of the present protocol is calculated and it is found to be higher than several existing bi-directional protocols.